Kitchen safety device and method for controlling operation of a heating appliance

ABSTRACT

A kitchen safety device automatically deactivates a heating appliance. The safety device includes an operator control panel which communicates with the appliance. The control panel includes input buttons for entering minimum weight and minimum time criteria for items placed on a cooking surface of the appliance. A weight sensor is operatively connected to the cooking surface of the appliance and communicates with the control panel. Upon activation of the appliance, the sensor operates to detect a positive application of the minimum weight onto the cooking surface within the prescribed minimum time. In the absence of a positive application within the prescribed minimum time, the sensor signals the control panel to deactivate the appliance.

TECHNICAL FIELD AND BACKGROUND OF THE INVENTION

This invention relates to a kitchen safety device and method for controlling operation of a heating appliance, such as a gas or electric stove or oven. The invention is applicable for both home use and in commercial kitchens.

Most kitchen fires occur because food is left unattended on the stove or in the oven. To address this problem, certain prior art safety devices have been developed to sense the presence of food on or inside the cooking appliance, and to provide an alarm or other indicator designed to alert the operator of the cooking food. While such devices may effectively limit the number of kitchen fires resulting from unattended cooking, they fail to address the problem of a heating appliance which has been inadvertently left on after the food item is removed. This situation presents an equally hazardous condition. Prior attempts to address this problem are of limited practical application. According to one such effort described in U.S. Pat. No. 6,253,761, the kitchen appliance utilizes a sensor device to detect the absence of a cooking utensil. If the cooking utensil is present on or within the appliance, then the appliance can be activated for normal use. If the cooking utensil is absent, then the appliance will not activate. While this device addresses the general problem, it overly restricts use of the kitchen appliance by, for example, limiting its ability to preheat in the absence of a cooking utensil. In addition, the device would fail to deactivate the appliance in the presence of an empty cooking utensil.

SUMMARY OF INVENTION

Therefore, it is an object of the invention to provide a safety device which effectively prevents inadvertent operation of a kitchen appliance.

It is another object of the invention to provide a safety device which is readily adjustable to enable normal intended uses of the kitchen appliance.

It is another object of the invention to provide a safety device which is either hard wired or which utilizes wireless technology.

It is another object of the invention to provide a safety device which is applicable for home use or in commercial kitchens.

It is another object of the invention to provide a safety device which may be factory installed inside the kitchen appliance or incorporated as a retrofit item.

These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a kitchen safety device for automatically deactivating a heating appliance. The safety device includes an operator control panel which communicates with the appliance. The control panel includes means for entering minimum weight and minimum time criteria for items placed on a cooking surface of the appliance. A weight sensor is operatively connected to the cooking surface of the appliance and communicates with the control panel. Upon activation of the appliance, the sensor operates to detect a positive application of the minimum weight to the cooking surface within the prescribed minimum time. In the absence of a positive application within the prescribed minimum time, the sensor signals the control panel to deactivate the appliance.

According to another preferred embodiment of the invention, the operator control panel includes an LED alert for indicating activation of the safety device.

According to another preferred embodiment of the invention, the operator control panel includes a message display screen for communicating a device status message to the operator.

According to another preferred embodiment of the invention, the operator control panel includes a system reset button.

In another embodiment, the invention is a kitchen heating appliance in combination with a safety device for automatically deactivating the heating appliance. The safety device includes an operator control panel which communicates with the appliance. The control panel includes means for entering minimum weight and minimum time criteria for items placed on a cooking surface of the appliance. A weight sensor is operatively connected to the cooking surface of the appliance and communicates with the control panel. Upon activation of the appliance, the sensor operates to detect a positive application of the minimum weight onto the cooking surface within the prescribed minimum time. In the absence of a positive application within the prescribed minimum time, the sensor signals the control panel to deactivate the appliance.

According to one preferred embodiment of the invention, the kitchen heating appliance is a stove.

According to another preferred embodiment of the invention, the kitchen heating appliance is an oven.

In yet another embodiment, the invention is a method for controlling operation of a heating appliance. The method includes the steps of connecting a kitchen safety device to the appliance. The safety device includes an operator control panel. Minimum weight and minimum time criteria for items placed on a cooking surface of the appliance are then entered into the control panel. A positive application of the minimum weight onto the cooking surface within the prescribed minimum time is then determined. In the absence of a positive application within the prescribed minimum time, the control panel is signaled to deactivate the appliance.

According to another preferred embodiment of the invention, the step of determining includes operatively connecting a weight sensor to the cooking surface of the appliance.

According to another preferred embodiment of the invention, the method includes the step of alerting the operator when the kitchen safety device has been activated.

According to another preferred embodiment of the invention, the method includes the step of communicating a device status message to the operator.

According to another preferred embodiment of the invention, the method includes the step of resetting the kitchen safety device after activation.

BRIEF DESCRIPTION OF THE DRAWINGS

Some of the objects of the invention have been set forth above. Other objects and advantages of the invention will appear as the description proceeds when taken in conjunction with the following drawings, in which:

FIG. 1 is a perspective view of the kitchen safety device according to one preferred embodiment of the invention, and showing the weight sensor positioned adjacent the eye of a stove;

FIG. 2 is a front view of the operator control panel and showing its connection to the weight sensor positioned adjacent the stove eye; and

FIG. 3 is a perspective view of a kitchen heating appliance with a portion broken away and showing the safety device operatively connected to the stove eyes and oven rack.

DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE

Referring now specifically to the drawings, a kitchen safety device according to the present invention is illustrated in FIG. 1, and shown generally at reference numeral 10. The safety device 10 is applicable for automatically deactivating a kitchen heating appliance 11 after a prescribed time delay, and in the absence of a food item carried on a cooking surface 12 of the appliance 11. The safety device 10 is especially adapted for stoves and ovens as a factory installed or retrofit item. The cooking surface 12 may be a stove eye “E” (or burner) or an oven rack “R”, as indicated in FIG. 3.

As shown in FIGS. 1, 2, and 3, the safety device 10 includes an operator control panel 15 which mounts on or adjacent the appliance 11, and is connected through wiring 16 and 17 to an existing appliance control knob 18 and a weight sensor 19. The control knob 18 cooperates with an electric switch to control activation and deactivation of the appliance heating element. The weight sensor 19 is operatively positioned adjacent the cooking surface 12 of the appliance 11. Examples of conventional weight sensors applicable in the present device 10 are disclosed in prior U.S. Pat. Nos. 6,253,761; 5,693,886; 5,486,685; and 4,672,181. The complete disclosure of these prior patents is incorporated herein by reference.

The control panel 15 has data input buttons 21 and 22 which allow the operator to preset minimum weight and time criteria for items placed on the cooking surface 12. The weight and time data are clearly displayed on the control panel 15, as indicated at 23 and 24, and are readily and conveniently adjusted by the operator using the up/down input buttons 21, 22. In one example, the minimum weight is set to 8 ounces with a minimum time limit of 1.5 minutes. In this case, upon activation of the appliance 11, the control panel 15 initiates an internal timer. The sensor 19 then operates to detect a positive application of at least 8 ounces onto the cooking surface 12 within the prescribed minimum time—1.5 minutes. In the absence of this minimum weight application, the sensor 19 signals the control panel 15 to immediately deactivate the appliance 11. Adjustability of the weight and time criteria helps limit unintended operation of the safety device 10. For example, the operator may desire to preheat an oven to a given temperature prior to placement of an item onto the cooking rack “R”. In this case, sufficient time is entered into the control panel 15 allowing the oven to preheat without triggering activation of the safety device 10. In another example, the operator may wish to boil water in a pot on a stove eye “E” prior to inserting a food item, such as pasta, for cooking. In this case, the control panel 15 is set to a minimum weight sufficient to account for the pot and water. If the operator fails to insert the pasta into the boiling water within the prescribed time limit, then the safety device 10 will automatically deactivate the appliance 11.

When the safety device 10 is activated, a flashing LED alert 31 located on the control panel 15 indicates to the operator that the heating element of the appliance 11 has been automatically turned off, and that the appliance control knob 18 should be rotated back to the “off” position. Preferably, a scrolling message screen 32 displays a message regarding the current status of the safety device 10. In the case of activation, the message may read “The Kitchen Safety Device has disengaged your cooking surface due to inactivity for 1 minute and 30 seconds.” A system reset button 33 clears the safety device 10 and allows the operator to resume normal use of the appliance 11.

A kitchen safety device is described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of the preferred embodiment of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation—the invention being defined by the claims. 

1. A kitchen safety device for automatically deactivating a heating appliance, said safety device comprising: (a) an operator control panel communicating with the appliance, and comprising means for entering minimum weight and minimum time criteria for items placed on a cooking surface of the appliance; and (b) a weight sensor operatively connected to the cooking surface of the appliance and communicating with said control panel, whereby upon activation of the appliance, said sensor operates to detect a positive application of the minimum weight onto the cooking surface within the prescribed minimum time, and in the absence of a positive application within the prescribed minimum time, said sensor signals said control panel to deactivate the appliance.
 2. A kitchen safety device according to claim 1, wherein said operator control panel comprises an LED alert for indicating activation of said safety device.
 3. A kitchen safety device according to claim 1, wherein said operator control panel comprises a message display screen for communicating a device status message to the operator.
 4. A kitchen safety device according to claim 1, wherein said operator control panel comprises a system reset button.
 5. A kitchen safety device for automatically deactivating a heating appliance, said safety device comprising: (a) an operator control panel communicating with the appliance, and comprising means for entering minimum weight and minimum time criteria for items placed on a cooking surface of the appliance, said operator control panel comprising: (i) an LED alert for indicating activation of the safety device; (ii) a message display screen for communicating a device status message to the operator; and (iii) a system reset button; (b) a weight sensor operatively connected to the cooking surface of the appliance and communicating with said control panel, whereby upon activation of the appliance, said sensor operates to detect a positive application of the minimum weight onto the cooking surface within the prescribed minimum time, and in the absence of a positive application within the prescribed minimum time, said sensor signals said control panel to deactivate the appliance.
 6. In combination with a kitchen heating appliance, a safety device for automatically deactivating the heating appliance, said safety device comprising: (a) an operator control panel communicating with said appliance, and comprising means for entering minimum weight and minimum time criteria for items placed on a cooking surface of said appliance; and (b) a weight sensor operatively connected to the cooking surface of said appliance and communicating with said control panel, whereby upon activation of said appliance, said sensor operates to detect a positive application of the minimum weight onto the cooking surface within the prescribed minimum time, and in the absence of a positive application within the prescribed minimum time, said sensor signals said control panel to deactivate said appliance.
 7. A combination according to claim 6, wherein said operator control panel comprises an LED alert for indicating activation of said safety device.
 8. A combination according to claim 6, wherein said operator control panel comprises a message display screen for communicating a device status message to the operator.
 9. A combination according to claim 6, wherein said operator control panel comprises a system reset button.
 10. A combination according to claim 6, wherein said kitchen heating appliance comprises a stove.
 11. A combination according to claim 6, wherein said kitchen heating appliance comprises an oven.
 12. A method for controlling operation of a heating appliance, said method comprising the steps of: (a) connecting a kitchen safety device to the appliance, the safety device including an operator control panel; (b) entering into the control panel minimum weight and minimum time criteria for items placed on a cooking surface of the appliance; and (c) determining a positive application of the minimum weight onto the cooking surface within the prescribed minimum time, and in the absence of a positive application within the prescribed minimum time, signaling the control panel to deactivate the appliance.
 13. A method according to claim 10, wherein said step of determining comprises operatively connecting a weight sensor to the cooking surface of the appliance.
 14. A method according to claim 10, and comprising the step of alerting the operator when the kitchen safety device has been activated.
 15. A method according to claim 10, and comprising the step of communicating a device status message to the operator.
 16. A method according to claim 10, and comprising the step of resetting the kitchen safety device after activation. 